Surface-coated titanium carbonitride-based cermet cutting tool having excellent chipping resistance

Abstract

A surface-coated titanium carbonitride-based cermet cutting tool is a surface-coated TiCN-based cermet cutting tool in which a Ti compound layer that is a hard coating layer is deposited as a first layer on the surface of a TiCN-based cermet body containing W and Mo, and a Mo-enriched layer having an average thickness of 0.5 to 10 nm is formed at an interface between a TiCN phase of the body and the hard coating layer.

The invention claimed is: 
     
       1. A surface-coated TiCN-based cermet cutting tool, comprising:
 a body made of a TiCN-based cermet containing a TiCN phase as a hard phase component and containing 1 to 10 at % of each of W and Mo; and 
 a hard coating layer which is a first layer deposited on a surface of the body made of the TiCN-based cermet and is formed of any of a Ti carbide, a Ti nitride, a Ti carbonitride, a Ti oxycarbide, and a Ti oxycarbonitride, 
 wherein a Mo-enriched layer having an average thickness of 0.5 to 10 nm is formed at an interface between the TiCN phase of the body and the hard coating layer. 
 
     
     
       2. The surface-coated TiCN-based cermet cutting tool according to  claim 1 ,
 wherein, in a case where the interface between the TiCN phase of the body and the hard coating layer is observed in a longitudinal section of the surface-coated TiCN-based cermet cutting tool, the Mo-enriched layer is formed at an interface having a length of 60% or more of that of the interface between the TiCN phase of the body and the hard coating layer. 
 
     
     
       3. The surface-coated TiCN-based cermet cutting tool according to  claim 1 ,
 wherein, in addition to the Mo-enriched layer, a W-enriched layer having an average thickness of 0.5 to 10 nm is formed at the interface between the TiCN phase of the body and the hard coating layer. 
 
     
     
       4. The surface-coated TiCN-based cermet cutting tool according to  claim 3 ,
 wherein, in a case where the interface between the TiCN phase of the body and the hard coating layer is observed in the longitudinal section of the surface-coated TiCN-based cermet cutting tool, the W-enriched layer is formed at an interface having a length of 60% or more of that of the interface between the TiCN phase of the body and the hard coating layer. 
 
     
     
       5. The surface-coated TiCN-based cermet cutting tool according to  claim 2 ,
 wherein, in addition to the Mo-enriched layer, a W-enriched layer having an average thickness of 0.5 to 10 nm is formed at the interface between the TiCN phase of the body and the hard coating layer. 
 
     
     
       6. The surface-coated TiCN-based cermet cutting tool according to  claim 5 ,
 wherein, in a case where the interface between the TiCN phase of the body and the hard coating layer is observed in the longitudinal section of the surface-coated TiCN-based cermet cutting tool, the W-enriched layer is formed at an interface having a length of 60% or more of that of the interface between the TiCN phase of the body and the hard coating layer.